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IHONMAN & V. VULLIEZ. PROCESS OF AND APPARATUS FOR THE MANUFACTURE OFWHITE LEAD.

Patented Jan. 3, 1893.

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A. HONMAN 86 V; VULLIEZ. PROCESS 01E ANDAPPARATUS FOR THE MANUFACTURE 0FWHITE LEAD No. 489,254". Patented Jan. 3, 1893.

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Uwrrnn STATES ANDREW HONMAN AND VICTOR VULLIEZ, OF VVILLIAMSTOYVN,VICTORIA.

PATENT @nrtcn.

PROCESS OF AND APPARATUS FOR THE MANUFACTURE OF WHITE LEAD.

SPECIFICATION forming part of Letters Patent N 0. 489,254, dated January3, 1893.

Application filed May 28, 1891. Serial No. 394,452. (No model.) Patentedin Victoria September 24, 1889, No. 7,127, and

in Tasmania October 8, 1890, No. 857.

To all whom it may concern..-

Be it known that we, ANDREW HONMAN, surgeon, a subject of the Queen ofGreat Britain, residing at Electra Street, Williamstown, in the BritishColony of Victoria, and VICTOR VULLIEZ, white-lead manufacturer, also asubj ect of the Queen of Great Britain, residing at Osborne Street,Williamstown, in the British Colony of Victoria aforesaid, have inventednew and useful Improvements in the Process of and Apparatus for theManufacture of White Lead, (for which the said AN- DREW HONMAN hasobtained Letters Patent in the British Colony of Victoria, datedSeptember 24:, 1889, No. 7,127, and for which we, the said ANDREW HONMANand VICTOR VUL- LIEZ, obtained Letters Patent in the British Colony ofTasmania, dated October 8, 1890, No. 857,) of which the following is aspecification.

This invention relates to a method of manufacturing white lead in whichthe roasted ore is subjected to the action of lead acetate, the clearsolution from which has a stream of carbonic acid passed through it, andits object is to obtain white lead which is in finer crystals and moreuniform in quality than when manufactured by the ordinary process.

It consists mainly in preserving the basic acetate of lead at a uniformtemperature of aboutl Fahrenheit throughout the whole of the operation.

In manufacturing white lead by our process we take the ordinary galenaand crush and wash it as in the ordinary manner. We then roast it in areverberatory furnace which has a more than ordinarily large area ofsurface relatively to the fire-place, and this latter is provided with aboiler arranged immediately above it for the purpose of providing asupply of steam which is conducted through a pipe or pipes just beyondthe bridge, so as to discharge a series of steam jets in the directionof and above the galena in course of roasting. By practical experimentsit has been found that great advantages are attained by roasting thegalena in the presence of steam.

Referring to the drawings, Figure 1 is a diagrammatic view of anapparatus for carrying my'process into effect. Fig. 2 is a View of oneof the cylinders. the settling tank. Fig. 4 is a plan of the same. Fig.5 is a view of the vat. Fig. 6 is a sectional View of the precipitatingvat. Fig. 7 and S are sectional views of the drying apparatus.

The galena is suitably roasted to drive off the greater part of thesulphur. When this has been accomplished we remove it from the furnaceand place it in one of a series of tinned copper cylinders (such as isshown in Fig. 2 of our drawings), F being a man-hole door through whichthe material is fed and G being a perforated false bottom covered withcoarse linen, and H a man-hole door for removing the contents after theyhave been treated. I is a pipe for conducting a stream of hot neutrallead acetate into this cylinder, and J is a pipe at the bottom for thepurpose of conveying this stream (which has then been converted intobasic lead acetate) to a settling tank shown in Figs. 3 and 4. Thehotlead acetate is supplied to this cylinder at about 15 Baum and iscontinued until it ceases to have any efiect on the material undertreatment, which is ascertained by testing the solution dischargedthrough pipe J.

The settling tank, which is represented in section and plan at Figs. 3and 4, is divided into two parts by a vertical partition L, one part ofwhich contains a series of baffle plates Z for the purpose of preventingthe stream of liquid rising too rapidly to the top and by compelling itto pursue a circuituous course to give greater opportunities for it todeposit any solid matter it may hold in suspension. The overflow fromthis half passes into the second half in which there is a discharge pipeM made of india rubber or other flexible material and having its mouthsupported by floats m so as to receive only the purer liquid which is atthe upper part of the vessel. The clear solution of basic lead acetatethus be ing discharged through pipe M is conveyed into a vat constructedas shown in Fig. 5, said vat being lined with tinned copper and itsbottom being made so as to converge toward the center. This we prefer toeifect by fill= ing up that portion of the vat marked 0 with cement. Tothe center of this vat we connect Fig. 3 is asection of a discharge pipeP which we provide first with a plug Q and secondly with a stop-cock Qso that both must be operated before the liquid can escape. To the plugQ is attached a rod q having a rack g at the top with which gearsapinion g byoperating which theplug Q may be either opened or closed.This vat has a lid or cover R which is securely fastened down by meansof two or more right and left hand screw-threaded rods rr provided eachwith a correspondingly screw threaded link 7', whereby the two parts ofsaid rods may be drawn closer together or vice-versa, as will be wellunderstood. The solution in this vat is kept at an even and regulartemperature of 120 Fahrenheit or thereabout by means of a worm S intowhich steam enters at s, and the exhaust from which finds its exit at s.In this vat we also provide a worm T arranged spirally so as to beparallel to the cemented sides of the vat. This worm is perforatedthroughout its whole length so as to admit of the escape of a stream ofcarbonic acid which is conveyed to it from any suitable source by meansof pipe 25, which of course is provided with a stop-cock t to cut oflfthe supply wheneverneeded. Bypreferenceweforcethestream of carbonic acidthrough said worm by means of a pump, and the result of this proceedingis to cause the basiclead acetate to precipitatelead carbonate-whitelead. When the solution, which is at first about 18 Baum, decreases to15 Baum, the supply of carbonic acid is cut oif and a few minutesallowed for the precipitate to settle down to the bottom from whence itis drawn through the pipe Pand is then immediately replaced by a freshquantity of clear basic lead acetate from the settling tank, shown inFigs. 3 and 4, so as to bring the solution again'to the density of about18 Baum when the supply of carbonic acid is again turned on and the sameoperation repeated. The lead carbonatewhite lead-which is thusdischarged through pipe P togetherwith its accompanying solution isconducted to a settling tank, where the white lead deposits itself andthe clear solution at the top is pumped back to a cylinder (such as isillustrated in Fig. 2) and when the oxide therein has been entirelydissolved the sulphate of lead, which forms a portion of the residue, isdissolved by a solution of caustic soda, caustic potash, or ammoniumacetate. The solution thus made is conveyed to a tinned copper pan, suchas shown in Fig. 6, wherein it is preferably maintained at a fairly hightemperature in order that finer crystals may be produced than wouldotherwise be the case,- and wherein the white lead is precipitated bymeans of a solution of carbonate of soda, potash or ammonium. The whitelead thus produced either from the decomposition of the sulphate of leador from the discharge from the vat (shown in Fig. 5) is first thoroughlywashed and then dried in an apparatus shown in Figs. 7 and 8; This drierconsists of a cast iron pan supported on a bed of bricks V, and the twoheating flues V. This apparatus is provided with metal lids \V, which itwill be seen are hinged at w, and are inclined at about forty-fivedegrees. The ends of the lids rest in a groove or channel X so that asthe vapor condenses on the lids W it runs down into this channeland isconveyed away outside of the pan. This pasty white lead should be spreadupon this pan three or four inches deep and kept there until thoroughlydried. hen dried it is broken up, pressed through fine sieves and packedfor transportation.

Having now-particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed we declare thatwhat weclaim is:

1. Thehereinbefore described processconsisting of reducing and roastingthe galena, subjecting it to hot neutral leadacetate, conveying theresultant basic lead acetate to a settling tank, discharging the clearsolution of basic lead acetate to a closed vat and maintaining it at aneven temperature, and subjecting it to the action of carbonic acid topecipitate the white lead,substantially as described.

2. The described apparatus consisting of a holder or receiver, asettling tank with connections from the receiver, a closed vat and apipe connection from the surface of the solution in the settling tank tothe vat, means for heating the contents of the vat, and means forsupplying the carbonic acid thereto provided with a discharge,substantially as described.

ANDREW I-IONMAN. VICTOR VULLIEZ. Witnesses:

WALTER SMYTHE BAYSTON, WALTER CHARLES HART.

